Don't clean off the factory lube, it's there to aid W break in, so just shoot it a whole lot, then clean it when you have it all broke in nice.
ETA: all you need to do is check the chamber and barrel for excessive filth and obstructions and if it looks all clear you are GTG, then just get busy shooting, and stop worrying.
I don't even use lube when I CC my Glock, I just try to keep it dust, dirt and lint free.
(Hey whats a few dry rounds up to a few Mag.'s in an emergency gonna hurt W a Glock.)
But if I was going to take it for a range session then I would lube it for sure.